scholarly journals Optimal Color Lighting for Scanning Images of Flat Panel Display using Simplex Search

2018 ◽  
Vol 4 (11) ◽  
pp. 133
Author(s):  
HyungTae Kim ◽  
EungJoo Ha ◽  
KyungChan Jin ◽  
ByungWook Kim

A system for inspecting flat panel displays (FPDs) acquires scanning images using multiline charge-coupled device (CCD) cameras and industrial machine vision. Optical filters are currently installed in front of these inspection systems to obtain high-quality images. However, the combination of optical filters required is determined manually and by using empirical methods; this is referred to as passive color control. In this study, active color control is proposed for inspecting FPDs. This inspection scheme requires the scanning of images, which is achieved using a mixed color light source and a mixing algorithm. The light source utilizes high-power light emitting diodes (LEDs) of multiple colors and a communication port to dim their level. Mixed light illuminates an active-matrix organic light-emitting diode (AMOLED) panel after passing through a beam expander and after being shaped into a line beam. The image quality is then evaluated using the Tenenbaum gradient after intensity calibration of the scanning images. The dimming levels are determined using the simplex search method which maximizes the image quality. The color of the light was varied after every scan of an AMOLED panel, and the variation was iterated until the image quality approached a local maximization. The number of scans performed was less than 225, while the number of dimming level combinations was 20484. The proposed method can reduce manual tasks in setting-up inspection machines, and hence is useful for the inspection machines in FPD processes.

Author(s):  
Sung Ki Kim ◽  
Joon Kang ◽  
Seo Young Kim

Light Emitting Diode (LED) begins to be applied as backlight system in a flat panel display because of local dimming function, wide color gamut, longer lifetime and environmental-friendly feature. The performance of LED device is strongly dependent on the operating temperature, however, the operation beyond temperature limit could cause the luminosity decrease, wavelength shift and lifetime decrease including failure of electrode soldering in the package. Therefore, the thermal management in a LED backlight system is crucial to guarantee the image quality and the reliability of the display. However, narrow volume of flat panel displays cause low convective heat transfer showing non-uniform temperature distribution over the panel. It deteriorates the image quality that the inherent temperature difference over the flat panel display backlight system. The objective of present study aimed to investigate the effect of LED alignment in a direct-illuminating type backlight system. It is discussed thermal characteristics of backlights in flat panel with LED light source and evaluated performance of the heat spreading system to ensure the reliability of LED backlight system.


2013 ◽  
Vol 42 (7) ◽  
pp. 768-771
Author(s):  
宋丽妍 SONG Li-yan ◽  
李俊凯 LI Jun-kai ◽  
牟同升 MOU Tong-sheng

2011 ◽  
Vol 32 (8) ◽  
pp. 809-815
Author(s):  
桂宇畅 GUI Yu-chang ◽  
林昊天 LIN Hao-tian ◽  
刘艳梅 LIU Yan-mei ◽  
张剑平 Zhang Jian-ping ◽  
文尚胜 WEN Shang-sheng

Author(s):  
Shida Tan ◽  
Richard H. Livengood ◽  
Dane Scott ◽  
Roy Hallstein ◽  
Pat Pardy ◽  
...  

Abstract High resolution optical imaging is critical in assisting backside circuit edit (CE) and optical probing navigation. In this paper, we demonstrated improved optical image quality using VIS-NIR narrow band light emitting diode (LED) illumination in various FIB and optical probing platforms. The proof of concept was demonstrated with both common non-contact air gap lenses and solid immersion lenses (SIL).


Author(s):  
Bahri Aydın ◽  
Armagan Ozgur ◽  
Huseyin Baran Ozdemir ◽  
Pınar Uyar Gocun ◽  
Mehmet Arda Inan ◽  
...  

2021 ◽  
Vol 13 (9) ◽  
pp. 4852
Author(s):  
Jack Ngarambe ◽  
Inhan Kim ◽  
Geun Young Yun

Spectral power distribution (SPD) is an essential element that has considerable implications on circadian energy and the perception of lit environments. The present study assessed the potential influences of SPD on energy consumption (i.e., considering circadian energy), visual comfort, work performance and mood. Two lighting conditions based on light-emitting diode (LED) and organic light-emitting diode (OLED) were used as proxies for SPDs of different spectral content: dominant peak wavelength of 455 nm (LED) and 618 nm (OLED). Using measured photometric values, the circadian light (CL), melatonin suppression (MS), and circadian efficacy (CE) of the two lighting sources were estimated via a circadian-phototransduction model and compared. Additionally, twenty-six participants were asked to evaluate the said lit environments subjectively in terms of visual comfort and self-reported work performance. Regarding circadian lighting and the associated energy implications, the LED light source induced higher biological actions with relatively less energy than the OLED light source. For visual comfort, OLED lighting-based conditions were preferred to LED lighting-based conditions, while the opposite was true when considering work performance and mood. The current study adds to the on-going debate regarding human-centric lighting, particularly considering the role of SPD in energy-efficient and circadian lighting practices.


2010 ◽  
Vol 82 (7) ◽  
pp. 2734-2742 ◽  
Author(s):  
Erin L. Ratcliff ◽  
P. Alex Veneman ◽  
Adam Simmonds ◽  
Brian Zacher ◽  
Daniel Huebner ◽  
...  

Endoscopy ◽  
2016 ◽  
Vol 48 (10) ◽  
pp. 934-938 ◽  
Author(s):  
Sho Sasaki ◽  
Jun Nishikawa ◽  
Hideo Yanai ◽  
Munetaka Nakamura ◽  
Junichi Nishimura ◽  
...  

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